Apparatus for breaking up a dehydrated food mass

ABSTRACT

Apparatus for breaking up a mass of a dehydrated food product into smaller, substantially uniformly sized particles. The apparatus includes a screen on which such a mass is deposited, and an elongated resilient power-driven wiper blade which wipes over the surface of the screen to engage any mass thereon, and to press it through the screen.

United States Patent 91 Miles APPARATUS FOR BREAKING UP A DEHYDRATED FOOD MASS [75] Inventor: Thomas R. Miles, Portland, Oreg.

[73] Assignee: Foamat Foods Corp., Corvallis,

Oreg.

22 Filed: Dec. 23, 1971 21 Appl. No.: 211,270

[52] US. Cl 241/95, 241/2921, 241/DIG. 3O [51] Int. Cl. B02c 23/00 [58] Field of Search 241/51, 89.3, 89.4,

241/95, 102, 274, DIG. 30, DIG. 31, 292.1

[56] References Cited 1 UNITED STATES PATENTS Carlino 241/893 1 June 12, 1973 2,953,179 9/1960 Friess 241/894 3,631,909 1/1972 Otto 241/894 R27,002 12/1970 Stephan 241/894 X Primary Examiner-Donald G. Kelly Assistant ExaminerGary L. Smith Atz0rneyJon M. Dickinson [57] ABSTRACT Apparatus for breaking up a mass of a dehydrated food product into smaller, substantially uniformly sized particles. The apparatus includes a screen on which such a mass is deposited, and an elongated resilient powerdriven wiper blade which wipes over the surface of the screen to engage any mass thereon, and to press it through the screen.

7 Claims, 4 Drawing Figures Patented June 12, 1973 2 Shouts-Sheet 1 j Thomas RMiles INVENTOR azzzf #41244 APPARATUS FOR BREAKING UP A DEHYDRATED FOOD MASS BACKGROUND AND SUMMARY OF THE INVENTION This invention pertains to the processing of dehydrated food products, and more specifically to apparatus for breaking up a mass of such a product into smaller particles thereof which have predominantly a substantially uniform size.

In one type of conventional process for preparing a dehydrated food product, such as a blueberry product, a liquid concentrate of blueberries is prepared into a stable foam through the steps of mixing in a gas, such as nitrogen, and a small amount of a suitable stabilizing agent. The foam is then spread in a thin layer on a traveling belt, with hot air directed against it to dehydrate it to produce a solid but porous rehydratable product.

The dehydrated product thus produced, which is in the form of a mat on the belt, is removed and broken into relatively large fragments, or masses, which may vary considerably in size. For example, such fragments might have linear dimensions ranging anywhere from a small fraction of an inch to several inches. Ordinarily, this breaking up of the mat is simply a consequence of the mat (which is rather fragile) being removed from the supporting belt.

Typically, it is desired to producesome final product, other than these randomly sized fragments, which is in a more convenient form for incorporation in other food products, such as bakery products, powdered drink mixes, and others. In most instances, it is desirable that the fragments mentioned be further broken up to produce smaller particles of substantially uniform size before further processing. Such uniformity tends to make storage, handling and measuring considerably more convenient, and in some instances, uniformity may be necessary if the product is to be acceptable for its final purpose. As an illustration, a manufacturer of a dry bakery product, such as a cake mix, may wish to incorporate in one of his mixes a certain amount of a dried blueberry product prepared through the process described briefly above. In particular, he may wish to incorporate a blueberry powder where particles therein have a certain size which is easily handled and controlled by the mixing equipment which he. employs in the making of his cake mix. Particles of the blueberry product which are appreciably larger than those which he desires may not blend in well with his mix, and their presence may create a quality control problem which he would not otherwise have. On the other hand, if particles appreciably smaller than those which he desires are included in the blueberry powder that he requests, these may be lost during screening and like operations which he may perform during the preparation of his mix.

A general object of the present invention, therefore, is to provide novel apparatus for breaking up considerablequantities of a dehydrated foot mass, such as those described above, in a way which produces, in a given operation, a predominance of particles thereof having a substantially uniform size.

Another object of the invention is to provide such apparatus which has a relatively simple and inexpensive construction, which is reliable and efficient in operation, and which has high capacity.

And it has been observed, for example, that any appreciable amount of tumbling together of fragments (such as those mentioned) during a breaking-up process, produces a considerable amount of abrasion, and should therefore be particularly avoided.

Thus, an important further object of the invention is to provide apparatus of the type indicated which is capable of handling a collection of dehydrated food fragments, or masses, and breaking them up as described, with minimal tumbling and abrading of the fragments.

Another factor to consider is that in certain applications it may be desirable to break up material which, after emerging as a dried' mat, has been suitably partially densified and compacted, and is in the form of randomly sized dense fragments.

Experience has shown such densified fragments are also easily abraded, and must be treated carefully in a breaking-up operation if the production of an excessive amount of fines is to be avoided.

Thus, still another object of the invention is to provide apparatus of the type above outlined which is ca pable of handling, satisfactorily, dehydrated food fragments of differing densitites.

According to a preferred embodiment of the invention, the proposed apparatus comprises a screen, or web, having intersticies (meshes) that are substantially uniform in size and related in size to the size of particles which are desired from the breaking-up process. The top surface of this screen receives fragments or masses, which are to be broken up, and working in cooperation with this screen is a power-driven rotary wiper having a plurality of radially extending elongated resilient blades that wipe over the top of the screen.

The lead faces of the wiper blades are disposed at acute angles to those portions of the screen immediately in 1 the fragments break up, with particles thereof falling through the screen. Observations of actual operations of such apparatus have shown that minimal tumbling occurs in the fragments on the screen, and that a very high percentage (i.e., about 60 to percent) of particles which emerge from the base of the screen have about the same size, which is close to the size of the meshes in the screen. And such occurs regardless of the particular density of the fragments which are broken Features which are believed to contribute to this desirable performance, wherein tumbling is held to a minimum, are that the blade which engages the screen is made of a resilient material and is yieldably biased (by a spring) against the screen. Also contributing to this desirable action, it is believed, is that the lead face of the blade is disposed at an acute angle to the portion of the screen directly in front of it. As will be further explained later herein, there seems to be a range of blade angles in which the best performance of the apparatus is obtained. It is believed that the ability of the blade to flex and to yield away from the screen enables it effectively to press fragments in front of it down against the screen rather than to cause such fragments to roll and tumble in front of it.

DESCRIPTION OF THE DRAWINGS These and other objects and advantages attained by the invention will become more fully apparent as the description which follows is read in conjunction with the accompanying drawings, wherein:

FIG. I is a fragmentary top plan view of apparatus constructed according to the invention;

FIG. 2 is a fragmentary side elevation of the apparatus, on about the same scale as FIG. 1, with portions broken away to illustrate details of construction;

FIG. 3 is a cross-sectional view taken along the line 3-3 in FIG. 1; and

FIG. 4 is an enlarged fragmentary view, similar to a portion of FIG. 2, illustrating a modified hub mounting in the apparatus.

- DETAILED DESCRIPTION OF THE INVENTION Turning now to the drawings, and referring first to FIGS. 1 and 2, indicated generally at is apparatus as contemplated herein for breaking up fragments, or masses, of a dehydrated food product. With several exceptions, which will be discussed more fully later, all of the parts in apparatus 10 are preferably made of a suitable corrosion-resistant and easily sanitized metal, such as stainless steel or aluminum.

Forming a base, or frame, in the apparatus is a hollow, cylindrical tube 12 disposed with its axis 12a substantially vertical. Tube 12 may be supported on any suitable external supporting structure through an annular angle bracket 14 which is secured to the outside of the tube by nut and bolt assemblies, such as nut and bolt assembly 16 shown in FIG. 2. In the particular embodiment of the apparatus being described herein, the inside diameter of tube 12 is about 16% inches. It will be understood that this dimension, and others that will be given later herein, are for illustration purposes only, and are not critical.

Mounted inside of tube 12, intermediate its upper and lower ends, is a circular and generally planar horizontal support grating 18, which is made up of an outer circular ring 20, and a central latticework of straight bars 22 disposed at right angles to one another. Ring 20 and bars 22 are joined together in any suitable manner, as by welding. The grating is mounted on the tube by means of nut and bolt assemblies, such as 'that shown at 24 in FIG. 2, which join the ring and tube. In the particular grating shown, the minimum spacing between adjacent parallel bars is about 1 inch. As can be seen in FIG. 1, the grating includes a relatively large rectangular central opening 26.

Extending into opening 26 from beneath the grating is the upper part of the housing of a hydraulic motor 28. The motors housing is secured by screws 30 to a circular plate 32 which is welded centrally to the tops of the bars in the grating. Plate 32 includes a central circular opening 34 through which extends the output drive shaft 28a of the motor. As can be seen in FIG. 2, shaft 28a extends a considerable distance above the top of plate 32. Motor 28 is connected to a suitable source of hydraulic fluid under pressure which is adjustable to vary the speed of the motor. Plate 32 has an outside diameter of about 6 inches. With operation of motor 28,

shaft 28a turns in the direction of arrow 35 in FIG. 1, at a speed within a range of about 50 to I50 revolutions per minute.

Supported on top of the annular exposed part of grating 18, between the inside of tube 12 and the outer circumference of plate 32, are annular and substantially planar screens 36, 38. Screen 36 is disposed immediately on top of the grating, and in the particular embodiment of the apparatus being described is made up of a conventional 4-mesh screen material formed from stainless steel wire. Screen 38 rests on screen 36, and is made up herein of a conventional I0 mesh screen material formed from stainless steel wire. Screen 38 is also referred to herein as a web. When viewed from above as in FIG. 1, screens 36, 38 have similar outlines, with outside diameters of slightly less than 16 and 9% inches and inside diameters of slightly more than 6 inches.

As will become apparent, the mesh size of upper screen 38 is what determines the ultimate size of the predominant particles that are produced as contemplated herein during operation of the apparatus. Screen 36 and grating 18, which have considerably larger openings than those in screen 38, function as a support means for screen 38. V

The inner circumferential margins of screens 36, 38 are held in place by means of an O-ring 40 and a circular clamping plate 42. O-ring 40 may be made of any suitable, easily sanitized resilient material, such as a urethane rubber material. This ring closely surrounds the outside of plate 32, and in the absence of plate 42 extends somewhat above the top surface of plate 32. Plate 42 has a slightly larger outside diameter than plate 32, and is secured thereto by screws 44. The outer circumferential marginal portion of plate 42 which extends radially beyond plate 32presses down against 0- ring 40. Plate 42 is provided with a central opening 45 which accommodates motor shaft 28a.

The outer margins of screens 36, 38 are held in place by means of an O-ring 46, which is similar in construction to O-ring 40, and a clamp ring 48. O-ring 46 has an outside diameter which substantially corresponds with the inside diameter of tube 12. The same is true with respect to the outside diameter of clamp ring 48. As can be seen in FIG. 2, where a radial cross section of the clamp ring is shown, the base of the ring is beveled as indicated for the purpose of holding O-ring 46 both against the top of screen 38 and against the inside surface of tube 12. Clamp ring 48 is secured to tube 12 by means of bolts 50 which are distributed around the circumference of the tube.

An alternate construction which can be used in the apparatus employs a pair of axially aligned tubes, in place of tube 12, having confronting, outwardly projecting flanges between which may be sandwiched the margins of screens 36, 38. In certain applications, such construction may be desirable.

Mounted on the upwardly projecting end of shaft 28a is a wiper mechanism, or means, 52 as contemplated herein including a central hub 54 which carries a plurality of radially outwardly extending elongated blade assemblies, such as assemblies 56. In the embodiment illustrated, the wiper mechanism includes six equally angularly disposed blade assemblies. It is, of course, ap- I preciated that a greater or lesser number of such assemblies may be used if desired.

Hub 54 is generally flat cylindrical in configuration, and includes a central bore 58 which receives the upper end of shaft 28a. The shaft and hub are keyed together by a key 60 (see FIG. I), and are locked together by means of an elongated set screw 62 which extends radially through the hub and is tightened against key 60.

Referring to all of the figures together,-each blade assembly 56 includes an elongated cylindrical arm 64. The arm extends radially from the hub to a point adjacent the inside face of clamp ring 48, with the inner end of the arm received in a suitable radially disposed accommodating bore provided in the hub. Each arm is fastened to the hub by means of a pair of set screws such as the set screws shown at 66.

Mounted on each arm 64 is a rigid blade holder 68 and a resilient wiper blade 70. In the embodiment illustrated, each blade holder is made up of an elongated tube, such as tubes 72, and an elongated plate, such as plates 74, welded along one side of the tube.

Tubes 72 are mounted on arms 64 as shown, with the arms extending freely through the tubes. Snap rings, such as those shown at 76, are fastened to the outer ends of arms 64 to prevent axial retraction of the blade holders from the arms.

Wiper blades 70 are preferably formed from a suitable resilient material such as nylon or Teflon. The blades have peripheral outlines which are somewhat similar to those of plates 74, with the exception that the lower margins of the blades extend slightly below the lower margins of the plates. This can be seen clearly in FIG. 3. The blades are attached to the plates in the holders through suitable fasteners such as those shown at 78.

As can be seen for the particular blade assembly illustrated in FIG. 3, the lead faces of the wiper blades (i.e., those faces which advance in the direction of arrow35 over screen 38 with operation of motor 28), are disposed at acute angles to the portions of screen 38 im,- mediately in front of them. In the embodiment illustrated, these angles are equal to about 45. The bottom edges of the blades are yieldably pressed (and slightly bent) against the top of screen 38 by means of biasing springs, or spring means, such as those shown at 80, which act between hub 54 and plates 74 in the blade holders. As can be seen, springs 80 are coiled around arms 64 immediately adjacent the outside of the hub, with one end of each spring anchored by a screw 82 to the hub, and the other end acting against an inside edge of a notch in the inner end of a plate 74. In apparatus 10, springs 80 are sized whereby they cause the lower edges of blades 70 to exert a force of about 5 pounds each against screen 38.

An alternate means may be employed for biasing the blades, such as flat (rather than coiled) springs which may be attached to the blade holders, and may act therebetween and hub 54.

Mounted on top of hub 54 is a hollow conical member 84 whose radial cross-sectional configuration is as shown in FIG. 2. As can be seen in this figure, at its lower end in FIG. 2, member 84 includes a downwardly extending rim 84a which fits snugly about the outside of the hub.

FIG. 4 illustrates a modified mounting for hub 54. In this arrangement, motor shaft 28a projects upwardly further than as illustrated in FIG. 2, and is threaded. Slidably mounted on and keyed to this shaft (by a key 90) is a sleeve 92 which is slidably received within enlarged central bore 58 in the hub. The hub and sleeve are keyed together by a conventional key (not shown). Seating against the top of the hub, immediately outwardly of the sleeve, is the downwardly projecting rim of a hollow cap 94. Cap 94 fits slidably over shaft 28a and sleeve 92. A nut 96 is screwed onto shaft 28a and engages the top of cap 94.

With such construction, it is a relatively simple matter to adjust the axial position of .hub 54 on shaft 28a by adjusting nut 96. Engagement of blades 70 and the upper screen, and stressing in the biasing springs for the blades, yieldably resists downward movement of the hub. This kind of adjustment is useful in changing the angular attitudes of the blades, and in changing blade pressure on the upper screen.

Explaining now how apparatus 10 performs, with motor 28 operating, dehydrated food fragments which are to be broken up are dropped onto the screen (in any suitable fashion) from above, with conical member 84 deflecting such fragments out onto the screen. Let us assume initially that the fragments which are to be broken up are of the relatively porous type. Such fragments, for example, might be expected to have a den sity of about 3 pounds per cubic foot.

As the blades in the wiper mechanism wipe over the top face of screen 38, they engage these fragments,

, pressing them down against the screenwhereuponthe fragments break up and pass through the screen. Observations have shown that this process takes place with only a minimal amount of tumbling occurring in. the fragments. With motor 28 operating continuously, fragments to be broken up may be supplied continuously to the apparatus, and experience has shown that under these circumstances the embodiment of the apparatus described herein is capable of handling mate rial at a rate of about 1,000 (or somewhat more) pounds per hour.

Screen analyses of particles passed through the apparatus in an operation such as that just described, have shown that a predominance of relatively uniformly sized particles, related in size to the mesh size of screen 38, are produced. More specifically, and in the case of porous fragments being broken up and passed through a l6-mesh screen (38), about to percent of the broken-up product is large enough to be retained on a 24-mesh screen, 15 to 20 percent of the product is large enough to be retained on a SO-mesh screen, and substantially all of the balance of the product is small enough to pass through a IOO-mesh screen. In most cases, all of the first two of these categoriesof particles (i.e., those particles which are large enough to be retained either on a 24-mesh or on a SO-mesh screen) are acceptable. The balance of the product, which for the most part will pass through a IOO-mesh screen, constitutes unusable fines.

It will thus be appreciated that the breaking-up operation performed by apparatus 10 results in a" predominance of substantially uniformly sized particles of acceptable size. In the particular illustration given, those particles which are large enough to be retained on a 24* mesh screen are the ones which are intended to predominate. Those that are large enough to be held on a SO-mesh screen, while smaller, are normally also acceptable. Itwill be appreciated that while there are, of course, some differences in the exact sizes of those particles which have been pressed through a lG-mesh screen and which are held by a 24- mesh screen, these differences are slight. As a consequence, such particles which are large enough to be retained on a 24-mesh screen are considered herein as having substantially uniform sizes.

As is well understood, a mesh in a 24-mesh screen is about two-thirds the size of a mesh in a l6-mesh screen. And, it should be noted that this ratio of mesh sizes generally defines the small range of particle sizes which are desired herein to predominate in a final product. In other words, were the top screen in the apparatus a 24- mesh screen, it is desirable that about 60 to 70 percent of what passes through this screen to be large enough to be retained on a 36-mesh screen.

Obviously, the particular predominating size-range of final particles which is desired is a matter of choice, and can be adjusted through the use of a screen 38 having an appropriate mesh size. For most applications involving the breaking up of a dehydrated food product, desirable top screen mesh sizes seem to be in the range of about lO-mesh to about 40-mesh; and tests with the proposed apparatus have shown entirely satisfactory performances with screens in this range of sizes. Such tests have shown that regardless of the particular top screen mesh size employed, the predominance (60 to 70 percent) of particles which pass through the apparatus to form a final product are large enough to be retained on a screen having meshes about two-thirds the size of those in the top screen used.

It has also been determined by tests, that this kind of performance is obtained in the breaking up of fragments having different densities. The illustrative density given above for a rather porous product is typically about the minimum density that is encountered. A typical higher density product which might be encountered, as in the case of breaking up fragments which have resulted from a compacting operation as outlined earlier herein, might have a density of about 40 pounds per cubic feet.

In some instances, in using the apparatus to handle denser products, it has been found desirable to employ both a slightly larger acute angle between the lead faces of the blades and screen 38, and a slightly greater blade force on screen 38. For example, in handling a product having a density of about 30 pounds per cubic feet, a better blade angle in many instances seems to be about 60 and a better blade force on screen 38 seems to be about 8 or 9 pounds. In all situations encountered in testing the proposed apparatus, entirely satisfactory performance has been obtained on all kinds of products of the type contemplated with a blade angle in the range of about 45 to 60, and a blade pressure in the range of about to 10 pounds.

As was mentioned briefly earlier, some of the features in the apparatus which are believed to accomplish the breaking up of fragments with minimal tumbling, are the acute angles between the blade faces and screen 38, and the fact that the lower edges of the blades are yieldably away from the screen. Both the resilience in the blade material itself, and the yieldability in springs 80 contribute to this.

While in most instances, a top screen 38 is entirely satisfactory, there are certain applications where in place of this screen, it is desired to use a perforated plate. Such a plate will, of course, perform in much the same manner as a screen. One advantage of using such a plate is that its top surface is considerably smoother than the top surface of the usual screen. As a consequence, there is even less of a tendency for abrasion to occur in a situation where such a plate is employed, and this may be important in certain instances.

Thus, while a preferred embodiment of the invention has been described herein, and certain modifications suggested, it is appreciated that other modifications and the variations may be made therein without departing from its spirit.

It is claimed and desired to secure by letters patent:

1. Apparatus for breaking up a dehydrated food mass to produce smaller particles thereof, said apparatus comprising a web having a generally upwardly facing surface for receiving such a mass, and including intersticies that extend completely through it opening to said surface, said intersticies all having substantially the same size, and

a movable power-driven wiper means positioned above said surface including an elongated blade mounted for movement in one direction along a path over said surface to engage any mass thereon, said blade having an elongated edge disposed adjacent and yieldably urged toward said surface and extending transverse to said path, and means pivotally mounting said blade for angular displacement of said edge about an axis extending parallel to said surface and transverse to said path.

2. The apparatus of claim 1, wherein said wiper means is mounted for rotation relative to said web.

3. The apparatus of claim 1, wherein said blade has a lead face which is disposed at an acute angle to said surface.

4. Apparatus for breaking up a dehydrated food mass to produce substantially uniformly sized smaller particles thereof comprising a screen having meshes of a substantially uniform size therein, said screen having an upwardly facing substantially planar surface adapted to receive such a mass, and

a power-driven rotary wiper mechanism disposed above said surface of said screen, said wiper mechanism including an elongated resilient blade mounted for movement along a path over said surface, said blade having a substantially planar lead face disposed at an acute angle to said surface and an elongated edge disposed adjacent said surface and transverse to said path, means pivotally mounting said blade for angular displacement of said edge about an axis extending parallel to said surface and transverse to said path, and spring means biasing said edge toward said surface of said screen,

said blade, with the wiper mechanism driven, being adapted to move over said surface and to engage and press against the screen any mass thereon.

5. The apparatus of claim 3, wherein said acute angle is about 45 to about 60 inclusive.

6. The apparatus of claim 3, wherein said wiper means includes spring means yieldably biasing said edge against the surface of the web.

7. The apparatus of claim 4, wherein said acute angle is about 45 to about 60, inclusive.

* III I 

1. Apparatus for breaking up a dehydrated food mass to produce smaller particles thereof, said apparatus comprising a web having a generally upwardly facing surface for receiving such a mass, and including intersticies that extend completely through it opening to said surface, said intersticies all having substantially the same size, and a movable power-driven wiper means positioned above said surface including an elongated blade mounted for movement in one direction along a path over said surface to engage any mass thereon, said blade having an elongated edge disposed adjacent and yieldably urged toward said surface and extending transverse to said path, and means pivotally mounting said blade for angular displacement of said edge about an axis extending parallel to said surface and transverse to said path.
 2. The apparatus of claim 1, wherein said wiper means is mounted for rotation relative to said web.
 3. The apparatus of claim 1, wherein said blade has a lead face which is disposed at an acute angle to said surface.
 4. Apparatus for breaking up a dehydrated food mass to produce substantially uniformly sized smaller particles thereof comprising a screen having meshes of a substantially uniform size therein, said screen having an upwardly facing substantially planar surface adapted to receive such a mass, and a power-driven rotary wiper mechanism disposed above said surface of said screen, said wiper mechanism including an elongated resilient blade mounted for movement along a path over said surface, said blade having a substantially planar lead face disposed at an acute angle to said surface and an elongated edge disposed adjacent said surface and transverse to said path, means pivotally mounting said blade for angular displacement of said edge about an axis extending parallel to said surface and transverse to said path, and spring means biasing said edge toward said surface of said screen, said blade, with the wiper mechanism driven, being adapted to move over said surface and to engage and press against the screen any mass thereon.
 5. The apparatus of claim 3, wherein said acute angle is about 45* to about 60* inclusive.
 6. The apparatus of claim 3, wherein said wiper means includes spring means yieldably biasing said edge against the surface of the web.
 7. The apparatus of claim 4, wherein said acute angle is about 45* to about 60*, inclusive. > 